1. Field of the Invention
The present invention relates to technology for using toner to develop an electrostatic latent image formed on a photoreceptor. More particularly, the present invention relates to a toner cartridge that accommodates toners and a developing device to which this is to be attached.
2. Description of the Related Art
An image forming device (e.g., a laser printer) having a photoreceptor uses a developing device. A toner cartridge is attached to the developing device. A standard developing device comprises a casing, a supply roller, and a developing roller. The casing has a space for housing the toner cartridge, and a developing chamber that communicates with the space. The supply roller and the developing roller respectively have a rotational axis that extends along the horizontal direction. The supply roller is housed within the developing chamber. The supply roller supplies toners that were sent to the developing chamber to the developing roller. The developing roller supports the toners supplied by the supply roller.
The developing roller is in contact with the photoreceptor. An electrostatic latent image is formed on the surface of the photoreceptor. The developing roller supplies toners to the photoreceptor. The toners will adhere to the electrostatic latent image portion of the photoreceptor. In this way, the electrostatic latent image of the photoreceptor will be developed.
An example of a developing device is disclosed in Japanese Patent Application Publication No. 9-319202. In this technology, toners circulate between the developing device and the toner cartridge. Two side wall openings are formed in a side wall that defines the developing chamber of the developing device. The two side wall openings are offset along the horizontal direction, and are located at the same height. In addition, two case openings are formed in the toner cartridge. The two case openings are offset along the horizontal direction, and are located at the same height.
When the toner cartridge is attached to the developing device, one of the case openings and one of the side wall openings face each other, and the other case opening and the other side wall opening face each other. In this way, the toner cartridge and the developing chamber communicate with each other. The toners within the toner cartridge are sent to the developing chamber via one of the case openings and one of the side wall openings. An auger is provided in the developing device. The auger transports the toners within the developing chamber from one of the side wall openings to the other of the side wall openings. The toners within the developing chamber are returned to the toner cartridge via the other of the side wall openings and the other of the case openings.